U.S. Transportation Secretary Ray LaHood forcefully denounced the EU’s emissions trading system (ETS) and said he is in talks with Secretary of State Hillary Rodham Clinton on enforcement measures.

Speaking at the FAA Forecast Conference March 8 in Washington, LaHood declined to elaborate on the specific nature of those enforcement measures. Visibly angry when speaking of the ETS, LaHood called the EU’s imposition of the system “one of the biggest irritations” of his tenure at the head of the U.S. Transportation Department. “This system makes no sense at all,” he said.

LaHood noted that the Obama administration’s environmental record is strong, so the EU need not have acted unilaterally. Pointing to the administration’s rule that raised the fuel efficiency limits for automobiles, LaHood said the EU should have come to the negotiating table with the U.S., airlines and manufacturers to set up a standard and system that would have worked for all stakeholders. What happened instead is “not the way we do business,” LaHood says. “They should have done it the right way,” he said. “This approach was totally wrong.”

The imposition of the ETS could be in violation of the U.S.-EU open-skies treaty, and LaHood says he is in talks with his counterparts in the EU to discuss these ramifications. “It is a very, very bad law they have passed.”

“There are some things we can do,” LaHood said, hinting at enforcement issues. “I’m working very closely with Secretary Clinton on the things we can do.”